© 2015 Elsevier Ltd. All rights reserved. Study objective: Widespread chest CT use in trauma evaluation may increase the diagnosis of minor sternal fracture (SF), making former teaching about SF obsolete. We sought to determine: (1) the frequency with which SF patients are diagnosed by CXR versus chest CT under current imaging protocols, (2) the frequency of surgical procedures related to SF diagnosis, (3) SF patient mortality and hospital length of stay comparing patients with isolated sternal fracture (ISF) and sternal fracture with other thoracic injury (SFOTI), and (4) the frequency and yield of cardiac contusion (CC) workups in SF patients. Methods: We analyzed charts and data of all SF patients enrolled from January 2009 to May 2013 in the NEXUS Chest and NEXUS Chest CT studies, two multi-centre observational cohorts of blunt trauma patients who received chest imaging for trauma evaluation. Results: Of the 14,553 patients in the NEXUS Chest and Chest CT cohorts, 292 (2.0%) were diagnosed with SF, and 94% of SF were visible on chest CT only. Only one patient (0.4%) had a surgical procedure related to SF diagnosis. Cardiac contusion was diagnosed in 7 (2.4%) of SF patients. SF patient mortality was low (3.8%) and not significantly different than the mortality of patients without SF (3.1%) [mean difference 0.7%; 95% confidence interval (CI) -1.0 to 3.5%]. Only 2 SF patient deaths (0.7%) were attributed to a cardiac cause. SFOTI patients had longer hospital stays but similar mortality to patients with ISF (mean difference 0.8%; 95% CI -4.7% to 12.0). Conclusions: Most SF are seen on CT only and the vast majority are clinically insignificant with no change in treatment and low associated mortality. Workup for CC in SF patients is a low-yield practice. SF diagnostic and management guidelines should be updated to reflect modern CT-driven trauma evaluation protocols.